car loses power and backfires when under any kind of load
12-03-2011 | 06:04 PM
#1
Thread Starter
Junior Member
Joined: Dec 2011
Posts: 7
From: pei canada
hey i have a 93 rx7 twin turbo that i bought a while back and been having the same problem for awhile now with no luck on tracking down the issue. when i start the car and take it out (cold) it seems to work great but once it warms up it starts to act up. it will idle ok and everything and i can drive it threw all the gears its just when i put any kind of load on it the car will start backfiring and jumping like it does when you have a boost leak but i done a pressure test and found no leaks. ive tried new plugs and wires , coil pack , boost sensor and nothing seems to be making any kind of difference . has anyone had any issues like this ? its a shame just having to look at the car and not be able to drive it .
12-20-2011 | 10:31 AM
#6
Senior Member
Joined: Mar 2005
Posts: 168
From: Reno , NV
usually backpresure will make it boost low, it was just a thought. the pre cat removal should be the first power mod on theses cars. like amp said it sounds like a fueling issue . how long have u had the car and were you aware of the problem when test driving it? could also be getting into fuel cut. the smic is extremely restrictive , a frontmount alone could raise your afrs a couple points easy. also is the car trying to boost before it stats to break up?
12-25-2011 | 08:36 AM
#7
Thread Starter
Junior Member
Joined: Dec 2011
Posts: 7
From: pei canada
the car had no issues when i first bought it . i drove it 1500 kms to get it home when i picked it up without any problems . the problems started a little after i put the front mounted cooler on actually. it was working fine and started to act up once and awhile and just kept getting worse till now it acts the same when the engine temp starts to climb . when you do a cold start and take it out right away it works fine boosts smooth and once the engine temp gauge starts to move then it backfires and wont boost past 0 kpa on the boost gauge before it starts acting up feels like someone is towing the car backwards and its got a major boost leak but all the lines are good and done a boost test on it and its all good .
12-25-2011 | 12:42 PM
#8
Senior Member
Joined: Oct 2002
Posts: 411
From: Lincoln Park,NJ
Double check that front mount and make sure it's not touching any wires or something else like a wire is been rubbing a metal somewhat that is slowing causing problems and it only happen after starting drving the car, which u make u think it only happen only when the engine is hot. I have strong feeling that there is a wire causing that problem.
12-27-2011 | 10:02 AM
#9
Senior Member
Joined: Mar 2005
Posts: 168
From: Reno , NV
you said front mount with stock twins , do you happen to have any plastic tubing left in the system or is it all hard pipe? how did you check for leaks? usually I'll cap od the turbo intake pipes , then find a large vac hose or boost ref hose and use 20psi of shop air via a blowgun with rubber tip. smoke machies dont really tell u alot since there meant for evap systems and only produce 2 psi.
12-31-2011 | 05:38 PM
#10
Thread Starter
Junior Member
Joined: Dec 2011
Posts: 7
From: pei canada
i still have the one plastic elbow off the turbos that go into all my hard tubing to the inter cooler then hard lines off that up to the plastic eblow on the intake. pressurized the lines by capping off one end and made another cap with a valve stem in the other end and put 20 psi in the system and it will hold it all day long so none of my lines to an from the intercooler are leaking . and yah the car will boost fine and run fine when its first started but u pound threw a few gears and then the engine temp comes up and it just falls flat on its face and starts its dog legging .